The present invention relates generally to a method and apparatus for determining when at least on individual equipped with a portable proximity detector comes within a predetermined range of a user who is also equipped with a similar portable proximity detector.
When participating in various activities, whether outdoors, on a school campus, in a shopping mall or the like, individuals, particularly children and young adults, would like to know if a friend or companion is nearby. While a large variety of personal locating systems such as a child monitoring system are available, these systems generally do not allow two individuals to monitor the location of each other. Rather, one individual, typically an adult, can monitor the location of a second individual, typically a child, using a low power radio transmitter worn by the child. In relatively simple systems the location of the child is usually monitored so that if the child leaves a predetermined area, the radio transmitter will inform the adult. In other systems the precise location of the child can be determined, but at the expense of a more complex and physically large monitoring unit.
Even in systems in which two or more monitors are employed, each monitor is usually preprogrammed to respond to a companion monitor. That is, the user cannot customize or program one monitor to identify or otherwise respond to other such monitors as the user chooses. For example, U.S. Pat. No. 5,298,883 shows a proximity alert system in which a pair of portable transceiver units transmits a coded signal that is picked up by the other unit. The strength of the received coded signal controls the rate of an audible beeper. The rate of the beeper indicates the approximate distance between companion units.
Accordingly, it would desirable to provide a compact and inexpensive system that is also flexible and programmable, and which alerts individuals equipped with companions units when they come in proximity of one another.
In accordance with the present invention, a portable proximity alert detector is provided for a user to determine when at least one companion comes within a predetermined range of the user. The device includes a receiving portion for wirelessly receiving a first signal encoded with a code identifying a companion and a transmitting portion for wirelessly transmitting a second signal encoded with a user identifying code. The device also includes a processor, a modulator operationally coupling the processor to the transmitting portion for modulating the user identifying code, and a demodulator operatonally coupling the processor to the receiving portion for demodulating the companion identifying code. A first memory segment is operationally coupled to the processor for storing companion identifying codes received by the receiving portion. A second memory segment is operationally coupled to the processor for storing companion identifying codes of companions whom the user desires to contact. A third memory segment operationally coupled to the processor for storing the user identifying code. A user interface is operationally coupled to the processor through which the companion indentifying codes of the companions whom the user desires to contact are programmed into the second memory segment. An indicator is provided for alerting the user when at least one companion identifying codes received by the receiving portion matches one of the companion identifying codes stored in the second memory segment.
In accordance with one aspect of the invention, a housing is provided in which is secured the receiving portion, the transmitting portion, the processor, the modulator, the first, second and third memory segments, the user interface, and the indicator.
In accordance with another aspect of the invention, the housing is configured as a keychain.
In accordance with another aspect of the invention, the receiving and transmitting portions are incorporated in a transceiver.
In accordance with another aspect of the invention, the user interface is an interface port for externally programming the companion identifying codes of the companions whom the user desired to contact into the second memory segment.
In accordance with another aspect of the invention, the interface port is selected from the group consisting of a serial, infrared, USB, Bluetooth, IEEE 802.11, and an IEEE 1394 port.
In accordance with another aspect of the invention, the indicator is a visual indicator.
In accordance with another aspect of the invention, the indicator is an audio indicator.
In accordance with another aspect of the invention, the audio indicator plays a sound sequence associated with the companion who has been identified as coming within the predetermined range.
In accordance with another aspect of the invention, the audio indicator plays a different sound sequence for each different companion who has been identified as coming within the predetermined range.
In accordance with another aspect of the invention, the first and second memory segments are volatile memory segments.
In accordance with another aspect of the invention, the third memory segment is a non-volatile memory segment.
In accordance with another aspect of the invention, a method is provided for determining when at least one companion comes within a predetermined range of a user. The method begins by storing an identification code of each companion whom the user desires to contact. A first signal encoded with a code identifying a companion is received over a wireless communication link. A second signal encoded with a user identifying code is transmitted over a wireless communication link. The received companion identifying code is compared with the stored identifying codes. The user is alerted when the received companion identifying code matches one of the stored identifying codes.